1. MEIOSIS Class Notes

2. Drosplia (Fruit Fly Study)
The Drosplia fly has 8 chromosomes.
This made is an easy species to study since four of the chromosomes came from the female and four from the male.

3. Homologous Chromosomes
Homologous Chromosomes have identical male and female parts.

4. Diploid Cell
Diploid Cells are cells that have both sets of chromosomes.

5. Haploid Cell
Haploid Cells are cells that have only a single set of chromosomes or half.

6. Meiosis
The process in which the chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell.

7. Interphase
The period of cell growth, DNA replication and cell maturation.

8. Meiosis I
The first part of gamete division.

9. Prophase I
Each chromosome pairs with its corresponding homologous to form a tetrad.
A tetrad is 4 chromatids.

10. Metaphase I
The spindle fibers attach to the chromosomes.

11. Anaphase I
The fibers pull the homologous chromosomes toward opposite ends of the cell.

12. Telophase I
Two new nuclear envelopes are formed.

13. Cytokinesis I
The cytoplasm pinches the cell into two new cells.

14. Meiosis II
The second part of cell division. No DNA replication round.

15. Prophase II
Two haploid cells are formed each with one half the number of chromosomes as the original cell.

16. Metaphase II
The chromosomes line up in a row.

17. Anaphase II
The sister chromatids separate and move to opposite ends of the cell.

18. Telophase II
Four new nuclear envelopes are formed.

19. Cytokinesis II
The cytoplasm pinches the cell into four new haploid cells.

20. Spermatozoa
The male gametes are called spermatozoa or sperm.

21. Egg / Ova
The females gametes are called egg or ova.

22. Mitosis vs. Meiosis
Mitosis produces 2 diploid cells with the DNA identical to the original parent cell.
Meiosis produces 4 haploid cells with one half the DNA as the original parent cell.

23. Mitosis vs. Meiosis
Mitosis is used as the body grows or is injured to replace old or damaged cells.
Meiosis is used for sexual reproduction.